What does your work at the Institute of Applied Magnetism focus on?
We study magnetic materials and we also measure magnetic fields, that is to say we focus our studies on the magnetic properties of materials. This is a highly interesting aspect of nanoscience as it enables multiple applications.
The topic of nanoparticles is one of great interest as, in the past few years, various techniques have been developed that have enabled us to see particles on a nanoscale and even manipulate these particles, both physically and chemically.
Thus, on having the possibility of entering this nanometric scale, a number of discoveries have been made about new properties of materials at this scale. It can be said that in all the fields of physics, chemistry, biology and even medicine, there has been a convergence to the nanometric scale which, with the discovery moreover of certain techniques, has enabled a huge explosion in research.
What applications do magnetic nanopartícles have?
For example, in the field of storage and treatment of information by magnetic means, what they have tried to do is to augment the density of information, i.e. the number of bytes per unit of surface. All this has led us to work on hard disks that have much greater capacity and faster speeds of reading and writing.
In the medical field magnetic nanoparticles have great potential opportunities for new treatments for cancer. These particles can be introduced into the human body where, thanks to their magnetic properties, they can be visualised and directed in order to selectively attack the damaged cancerous tissue, leaving healthy cells intact.
If, for example, there is a tumour on the knee, it is desirable for the anti-cancer drugs only to act on the knee. This would greatly reduce the negative impact on the patient, in comparison to current treatment which are highly aggressive for the entire organism. One of the main advantages for medicine is that magnetic particles can transport drugs to the appropriate spot.
Another advantage to mention is that they can also be used in what is known as hyperthermia. This involves grouping the magnetic particles in the tumour, applying an external, high-frequency magnetic field which will produce the warming-up of these particles and thereby, a heating of the tissue in which these particles are present, and the thermal death of the cancerous and malignant cells.
What is basically interesting about magnetism is its capacity for storing the particles in one place in concrete, both regarding the aspect of tumours in the case of medicine, as well as the aspect of informatics (the more particles there are, the more bytes).
You also work with magnetic semiconductors in the field of informatics. What characteristics do these semiconductors have?
Today, one of the other highly important aspects of magnetism is what is known as magnetic semiconductors. The reason is very simple: a computer has a hard memory which is magnetic; as well as a ram memory – a memory of transistors which is electronic and is known as rapid memory. Rapid memory acts very rapidly and when energy goes, for example when the current is switched off, it disappears. Everybody, when there has been a power cut, thinks, “if that hadn’t been saved!” The hard memory is what has saved it. They are two distinct mechanisms.
When you switch on the computer and see little lights blinking, this is when the connection is being made between the hard memory and ram memory. In reality, it is a waste of time because, if we had magnetic semiconductors, it would be possible to carry this out in one step. Moreover, it could be rapid and permanent at the same time. And there would be no need for two systems.
In short, magnetic semiconductors would enable the computer to have just one system and not two memories, all information being automatically saved as one goes along. This is the task that many researchers, ourselves included, wish to solve from a nanometric scale perspective.
To date, we have found ZnO nanoparticles, which are semiconductors, that can make themselves magnetic – as we have done with gold, coating these ZnO particles with sulphur atoms. Maybe this could be applied to the computer field.
Effectively, during this research there were some big surprises such as the magnetic properties of gold nanoparticles.
That is correct. Gold is not a magnetic material; it is diamagnetic, a material that when a magnet (a magnetic field) is brought near it, it repels it. Nevertheless, nanoparticles of gold, on being coated with certain organic particles, can acquire magnetic properties, lacking in gold in its habitual state and as we know it in rings and chains.
These nanoparticles are of nanometric size and, chemically coated with atoms of sulphur, become magnetic. The exact mechanism behind this amazing discovery is still not known but it is something that we are investigating. It is a highly significant discovery as gold is a material of very low toxicity for the human organism.
At what point are these studies and, in general, nanotechnological research?
We will say that, at this point in time, we are at a high point in the various disciplines regarding the field of nanotechnology. Undoubtedly, it will have to progress further, but we can say that it is at that point of being an increasingly determinant factor, where greatest growth in interest is appreciated.
In medicine, they are studying and trying to do all that they were talking about a couple of years ago. Certain nanotechnology centres are already doing experiment with rabbits, etc. and are at a clinical trials stage in their research. I could not venture a timetable for all this but they are working on it and, from this, other things will surely arise.English translation by: WORDLAN firstname.lastname@example.org; 615740862.